This invention relates to an improved packaging device for filling formed and sealed tubular materials with pumpable products such as food products and for attaching double metal clips to the casing at intervals thereby enclosing or sealing the product in link form.
Various pumpable products, such as food products, and especially sausage or cheese, are packaged in tubular materials by attaching metal clips at spaced intervals thereby sealing and closing product within the tubular materials. Klenz in U.S. Pat. No. 3,383,754 issued May 21, 1968 discloses a device especially adapted for applying U-shaped metal clips about casing. Specifically, Klenz teaches the use of a punch for driving a U-shaped metal clip down a channel against a die to thereby form the clip about gathered casing retained at the bottom of the clip channel.
Klenz in U.S. Pat. No. 3,543,378 discloses the use of a pair of clippers arranged in tandem and cooperative with opposed movable casing gathering plates that define a pair of clip channels. The gathering plates move in opposition to each other to gather casing material into a constricted form or mass. Two U-shaped metal clips are then driven by punches about the gathered casing to seal the ends of the casing. A knife then cuts the casing between the clips to thereby separate the links defined by the clipped casing. Klenz in U.S. Pat. No. 3,583,056 discloses another clip attachment apparatus wherein a movable jaw pivots against a fixed jaw to gather the casing in a constricted region prior to attachment of a clip about the casing. Other patents disclose various combinations of gathering mechanisms for gathering casing prior to attachment of a clip or clips including Dobbert in U.S. Pat. No. 3,783,583, Velarde in U.S. Pat. No. 4,001,926, and Velarde in Reissue Pat. No. 30,196.
To increase the efficiency and utility of such clipping devices, it has been suggested in Andre U.S. Pat. No. 3,795,085 to mount a single clipper at a work station of a rotating table. A filled bag or casing which is to be clipped is placed on a nozzle at a first work station associated with the table. The casing material is then clamped as the table rotates to a second work station. Air in the casing is then evacuated through a vacuum system at a third station and ultimately, upon further rotation of the table to the clip work station, a clip is attached to the casing to seal the casing.
Andre in U.S. Pat. No. 4,578,928 discloses yet another variation on this theme wherein a circular table is provided for gathering casing material fitted about a product and evacuating the casing material before finally placing a clip about the gathered casing material at a final work station. Ailey U.S. Pat. No. 4,189,897 discloses a packaging device wherein product is placed in casing material and the material is then gathered and clipped by means of a U-shaped metal clip. The '897 patent discloses a continuous line operation device having a series of stations placed on an endless belt with means provided for each station to evacuate the casing, gather the casing, and attach a clip thereto.
While the aforesaid devices have been useful, there has remained a need for a high speed continuously operable packaging device for attachment of metal clips to generally cylindrical, continuously filled casing. Such a need has been particularly acute with respect to the desire to form links of casing of variable length and diameter without major adjustment or alteration in the operation and configuration of the packaging device. Objectives of this general nature led to the development of the present machine which is especially useful for the manufacture of chubs and other sausage and link-type products having a wide variety of length and diameter.